<meta charset="UTF-8">
<title>星星消消乐</title>
<link rel="stylesheet" href="./demo.css">

<div style="display:inline-block;width:200px;height:30px;border:5px solid #fff">
    <span style="display:inline-block;width:200px;height:30px;background: red;"></span>
</div>

<script src="./demo.js"></script>